Symptoms
- Grass left taller on one side of the mower
- Wavy or stripy pattern in the lawn
- Cut height looks different from left to right
- Deck may look tilted when viewed from the front
Likely causes
- CommonMower deck not levelIf the deck sits higher on one side, that side cuts shorter than the other.
- CommonUneven tire pressureA low tire on one side or corner tilts the deck and changes cut height there.
- CommonBent or dull bladeA blade bent even slightly changes its cutting arc and height.
- PossibleWorn wheel height adjustersMismatched height settings on each wheel produce an uneven cut.
What to do
- Park the mower on a flat, level surface and check tire pressure on all wheels, inflating to the same PSI per the manual.
- Disconnect the spark plug wire, then measure blade tip height off the ground at the front, back, left, and right of the deck.
- Adjust the deck leveling bolts (usually front-to-back and side-to-side adjusters) until measurements are even, per the owner's manual.
- Check that all four wheel height settings match; reset any that were bumped to a different notch.
- Inspect the blade for visible bending or uneven wear, and replace it if it's not straight.
- Test cut a small area and re-measure if the unevenness continues.
Tools and parts
- Tire pressure gauge
- Tape measure
- Wrench set
Replacement mower bladeSearch: “lawn mower blade replacement”
When to call a pro
If the deck won't level out with adjustments, a mower shop can check for a bent deck frame or spindle.
Safety
Use caution
Always disconnect the spark plug wire before reaching near or measuring around the blade.